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T. H. ABERGROMBIE.

MILLSTONE DRESSING MACHINE.

Patented July 26,1881.-

J91 0e 71 60 z" I UNITED STATES PATENT OFFICE.

THOMAS H, ABERCROMBIE, or HARRIS, GEORGIA.

MILLST ONE-DRESSING MACHINE.

SPECIFICATION forming part of Letters Patent No. 244,838, dated July 26, 1881.

' Application filed May 5,1881. (No model,)

the art to which it appertains to make and use the same, reference being had to the accompanyin g drawings, and to letters or figures of reference marked thereon, which form a part of this specification.

Figure 1 is a perspective view of the entire device. Fig.2 is a side elevation of the picker, its shaft, and means for raising or regulating it. Fig. 3 is a detail showing cam-slot in the pickershaft.

This invention belongs to that class known as millstone-dressing machines, and the novelty consists in the details of the construction, and in the combination of the several portions whereby a structure of few parts, easily made, strong and durable, and readily repaired, is produced, all as will now be more in detail set out and explained.

In the accompanying drawings, A denotes any suitable and usual frame on which the operative parts are mounted on the track a composed of two parallel horizontal bars extending from end to end of the frame, and near its upper part.

The mechanism is contained in a truck or case, B, suitably mounted on said track a by rollers b, by means of which it can be moved to and fro on said track. 0n the outside of said rollers are flanges or guard-strips b, to prevent the rollers coming off the said track sidewise. In one side of this case B is pivoted the gear-wheel O, which is operated by a crank, 0, and by any suitable power connected therewith. This gear-wheel meshes with a pinion, D, above it, which has a pin or arm at eccentrically attached to it, working in a curved slot, 0, in the upper end of the picker staff or rod E. This staff-rod is placed inside the casing E, held in proper guides on the side of the truck or case B, and when the gear-wheel is revolved is caused by the operation of pin cl in slot 0 to have an alternately rising and on the bolt or pivot f, by which it is hinged in the foot-piece.

The belt L, secured at each end of the machine and passing around the shaft which turns the gear-wheel O, causes the truck or case B to move forward or back along the track a, as may be desired, and regularly with the operations of the picks, when they are Worked by the above-described means.

At right angles to the tracks a, and at their ends where they meet the end of the machineframe, is a track or slot, a, in the frame A, in which this trackamay be moved sidewise back or forth from front to rear of the machine, and to any convenient place, by means of the screwshaft m, operated by the handle and wheel M.

The set-screws N on the lower edges of the frame, on each side, will enable the machine to be set in proper position to dress light or deep at the eye or the rim of the stone.

The picker-staff E can be raised or lowered by means of the wheel 0 on its screw-threaded top 6', said wheel being held in support 0 on the case E or truck B, and by means of the setscrew p in the case in which the staff moves the staff may be secured in any desired vertical position.

Instead of the casing E for the picker-staff any suitable guides may be used.

The device as thus constructed is very cheaply made, and will operate in the most effective manner. Being very strong it will wear a long time, and being very simple in structure it can be very easily repaired.

I am aware that heretofore in millstone-dressin g machines the picks have been worked by means of a hammer operated by atrip mechanism independentof it; also, that means have been used to place the stone in proper adjustment with the picks but in none of these ma actuated as described, the picker-staffcase E, staif E, having screw-threaded end a, and ad- 15 justable wheel 0, substantially as described.

3. The picker-case F, having picks F, and pivoted to the staff E, and adjustable by means of set-screws h and i, substantially as described.

In testimony whereof I aifix my signature 20 in presence of two witnesses.

THOMAS H. ABEBCROMBIE.

Witnesses:

JNo. E. ROAOH, ANDERSON ARNOLD. 

